StoreAppLevelSecret.js

const { SecretManagerServiceClient } = require('@google-cloud/secret-manager');

const secretManagerclient = new SecretManagerServiceClient();
const parent = 'projects/<YourProjectId>';
const tokenId = <YourTokenId>

async function getSecret() {
    const [version] = await client.accessSecretVersion({
        name: parent + '/secrets/' + tokenId + '/versions/latest',
    });

    // Extract the payload as a string.
    return version.payload.data.toString('utf8');
}